Downflow sheet drawing apparatus



Oct. 27, 1931. Q E, FERNGREN 1,829,641

DOWNFLOW SHEET DRAWING APPARATUS Original Filed Oct. 29, 1924 alG INVE NT UR. Enoch T Tmgreq.

9M3 ATT RNEI Patented Get. 27, 1931 warren STATES PATENT OFFICE ENOOI-I T. FER-NGREN, OF TOLEDO, OHIO, ASSIGNOR TO THE LIBBEY-OWENS-FORD GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO DOWNFLOW SHEET DRAWING APPARATUS Application filed October 29,1924, Serial No. 746,655. Renewed October 16, 1929.

The present invention relates to the process and apparatus for drawing sheet glass, and has particularly reference to a so-called down flow apparatus where the streams of glass comprising the finished sheets are flowed down the sides of a suitable slab.

An object of this invention is to provide an apparatus of this nature wherein a stream of glass is flowed down opposite sides of a 1 suitable slab having preferably converging sides, the said slab having means to intercept the downward flow of the streams to build up a reservoir from which a uniform stream flows, after which the streams merge at the endof the slab and are drawn therefrom in united sheet form.

A further object. of the invention is to provide a sheet drawingfapparaius of this nature wherein a stream of plastic glass is flowed down opposite sides of a slab having convergent sides and including means wherein the flow of the streams is so vcontrolled thatthe temperature and thickness properties ofthe streams can be controlled to produce a uniform sheet of glass.

" Still. another object. of the invention is to provide a sheet drawingappara' ius of this type wherein a stream of glass is flowed down opposite sides of a slab havingconvergent to sides and having means associated with the slab to form suitable edges of suflicient stability to hold the sheet to width after it has left the slab.

Other objects and advantages of the invention will become apparent during the course of'the following description.

In the drawings wherein like numerals are employed to designate like parts throughout the same.

Fig. l is a side elevation, partly in section, of the apparatus in use,

Fig. 2 is a section taken substantially on line 22 of Fig. 1. 1 i Fig. 3, is a sectional, View of a slightly .modified construction.

Fig. 4 is a top plan view of the apparatus, and Fig. 5 is a' detailsectional viewof one of the cooling shoes. I

Q In the drawings wherein forthe' purposes of illustration is shown the preferred embodiment of the invention, the numeral 5 designates an adhesion block or slab which is preferably formed from a refractory material, although it can be formed from a heat- -resisting metal such as nichrome, monel, etc.

R pass through the opening 11 is. controlled by means of suitable gates or valves 13. The glass flows from the furnace chamber 14 through the conduits 10, which, as shown in Fig; 4, are arranged at both sides of the slab 5. In this manner a quantity of glass is introduced within the trough 8 at both ends of the slab. The glass is continuously fed into the trough 8 so that an overflow takes place, and streams of glass 15 flow down both sides of the slab. In order to get a substantially uniform overflow, the side walls of the trough 8 are curved as at 16, while the bottom of the trough is arched as at 17 thus producing" a more shallow depth of glass in the trough at the center thereof than at the ends. The object of this arrangement is to gradually re duce the depth of the glass body towards-the central portion of the trough for the purpose of reducing the heat volume contained so that the glass at this point will not become hotter and more fluent by reason of its position within the heating enclosure 18. By having the side walls'of the trough 16 slightly lower in the center an accurate overflow will be had at the central portion of the block. This overcomes the retarding influence ofthe inner walls of the trough in the slab.

In orderto compensate for any irregularities in the overflow of the glass down the sides of the slab as regards the comparative temperatures of variouspoints along'thestreams and the thickness of the'sheet, I form on the slab, preferably near its lower edge thereof,

" transversely arranged projections 19 which preferably extend throughout the entire width of the slab. The projections'19 in 5 reality form'a ledgewhich has a tendency to intercept and retard the'down flow of glass on the sides of the'slab; thus forming what is termeda reservoir 20 from whichrthe final flowoof glass comes. 7 The source of glass. tormtions of the glassand also permitting a uniform thicknessofstream toflow fromtheresif ervoir with the result that the two streams mergin'g at theslowerend ofthe slabwill be uniform iii-thickness, thus producing a sheet '21 which" will" practically have a uniform thicklpess throughout its' entirelength and Widt "i 1' sheet to narrow after it leaves-the ends of the "slab, I employ shoes '22 arranged at both edges ofthe streams" flowing down the slab Y 's'i'red. 'lheis'hoes 22' cooltheborder sections ot the 1 streams sufficiently that when the sheet leaves thellower-end' of the slab they will be rigid enough toovercome the natural "tendency of the; sheet to narrow. ,A; pair' of smooth or knurled rollers23may bearranged below the slabto engage withthe border portiohsof the sheet to hold the same to width. The rollers 23' are mountedupon aflsuitahle' carriage and d-riving'"'mechanism" 24, v' The hoe's'aa mayor -may'fnot be used-in conjunc- -tion with the" rollers, 7 as desired; The heat- ;ing' enclosure 18 is'preferably provided with a lining 25 formed vfrom a refractory maten 'ature that it ispossibleito have uniform temperature condi-tions'therein, thus aiding "in theformation O fQtheSheetbeing drawn.

The lower end of the enelesure 18 isclosed by means of a sectional movable ;wall 26. Each section 'isflr'nounted upon a base 2 7 which 'may haVeQrOlIers-TZS movableon a rail 29. 'In this manner the sections can bemoved'to or V from the sheet, 'thus"makingrit possibleto 50 "accuratelycontrol temperature conditions for the purposes set forth; "As shownlin Fig. =2, the shoes 22* are carriedupon a shaft 30 -"passing through an i 'opening formed in the blocked A thumb screw 31 is provided to hold the shaft 30 inthe' desired adjustment. Each sha'ftSOis' preferably hollow as illustrated in Fig.5;and has arranged therein a 'edge's of zwhich. are" arranged the'shOe's 22 for the "reservoir; will have tendency to; ;j spread out, along the projections '19, thus equalizing the various temperature condie;

To'overco'me the natural tendency of the which-maybe hollow' and water cooledif derial. 'Thelheating' enclosure 18 is of such a controlling the temperature of the border portions of the streams being flowed down the slab so the sheet will not narrow after it leaves the end of the slab.

In the foregoing it will be seen that I form a sheet of glass by-fiowinga stream of plastic glass down both sides of a slab, and

utilize-means on the slab for retarding the down fiow for the purpose of'building up a reservoir. r The function of the reservoir is to make it possible to control andequalize the temperature conditions throughout the entire width of the streams and also to make un form"-thejthicknessof the stream after it leaves the reservoir. In this manner the streams, when vmerging at thelower end of the slab, wil l'have a'substantially uniform It is to beunderstoodthat the of the invention herewith shownanddescribed is to be takenas the preferred embodiment of .the

"same, and that various changes in the shape,

sizeand arrangementv of parts may be resorted-to' without departing from the spirito-i.

the invention orthe scope of the subjoined claims. x f Claims: '2 r r 1. In the'art of drawing sheet glass, a slab,

means to flow astream of glass down both sides of the slab, and means carried by each side of theslab to buildupareservoir from which flows a uniform stream of glass, the

two'streams merging at the end of the slab from where they are drawn in 'sheet fOrm."

' 2. In the art of drawing sheetglass,.a slab, having downwardly convergent sides means to flow glass down both sidesof the slab and to-draw the streams from the. slabiin sheet form,' and means projecting outWardlyfrorh the slab to build up ajreservoirofglass between its introduction to the:slab and the point'where it is drawn from the slab to producea smooth uniform sheet of glass. 7 w p 3 In the art of drawing sheet'glass, a slab, means to flow astream of glass down both sides of'the slab and to'draw thesame there- I from in sheet form, and means on the slab to control the flow ofglassfrom the sides of theslab; 1 V

4. In the art of drawing sheet glass, a-slab,

means-to flow-a stream of glassdown both sidesof the slab, and means on the slab for intercepting the flow of glass down the slab to build up a'reservoir for equalizing'the temperature and uniformity-of the sheet being drawn;

U 5. In the art of drawing she glass,- a slab,

"means to flow a stream of glass down both sides of the slab, meansformedon the slab and transversely thereto "for retarding the movement of the glass down the sides of'the sla-b to equalize the same; and means for drawing the streams'from the end-of the slab inunited sheet form.

thickness, thus producing a smooth uniform sheet of glass; I

6. In the art of drawing sheet glass, a slab, means to flow a stream of glass down both sides of the slab, an enlarged portion formed on the slab between its ends and arranged transversely thereof for retarding movement of the streams to build up reservoirs for equalizing the temperature and uniformity of the streams, and means for drawing the streams from the end of the slab in united sheet form.

7. In the art of drawing sheet glass, a slab having downwardly convergent sides, said slab having a trough formed in its upper end for the reception of a continuous feed of molten glass from where it overflows and passes down the sides of the slab in streamlike formation, means formed on the slab and arranged transversely thereof for retarding the downflow of glass to build up a resevoir for equalizing and making uniform the temperature and thickness properties of the streams, and means for drawing the s ream from the slab in united sheet form.

8. A slab for use in sheet glass apparatus having convergent sides and an enlarged portion formed thereon and extending laterally thereof.

' 9. A slab for use in sheet glass apparatus having downwardly convergent sides and projections formed on both sides of the slab and extending transversely thereof.

10. A slab for use in sheet glass apparatus having downwardly convergent sides, projections formed on both sides thereof and between its ends, said projections being arranged transversely and extending throughout the entire width of the slab.

11. In an apparatus of the class described,

' a vertically disposed directing member down and from which molten glass flows in sheet form, and means mounted on said member arranged intermediate the top and bottom of the member at one side thereof and extending horizoni ally throughout the major portion of its width for coaction with the glass flowing down the same to regulate the thickness of the glass stream throughout il's width, said means projecting outwardly beyond the sides of the body of said directing member.

12. In an apparatus of the class described, a vertically disposed directing member down and from which molten glass flows in sheet form, the opposite sides of which member taper inwardly toward the lower end thereof,

and horizontally disposed glass controlling means arranged at opposite sides of said member and integral therewith and extending horizontally substantially throughout the width of the respective sheets, said glass controlling means projecting outwardly beyond the sides of the body of said directing member.

13. In the art of drawing sheet glass, a slab, means to flow a stream of glass down both sides of the slab and to draw the streams from the slabiin sheet form, and meanson the'slab to retard the movement of the streams duringtheirfiow down the sides of the slab, said last mentioned means projecting outwardly beyond the sides of the body of said slab.

14. In the art of drawing sheet glass,- a slab, means toflow a stream of glass down bothsides of the slab, at the end of which they merge and are drawn from tlie slab-in sheet form, and means on the slab to build up a reservoir of glass onboth. sides of the-slab to create a constant uniform flow at a point just prior to the merging of the streams to Jroduce a uniform sheet of lass said last mentioned means projecting outwardly beyond the sides of the body of said slab.v v

e 15. In the art of drawing sheet glass, a slab, means to flow a stream of glass down both sides of the slab and to-draw the same therefrom in sheet form, a projection ar-' ranged transversely along both sides of the slab for re arding movement of the glass down the sides of the slab.v

16. In the art of drawing sheet glass, a slab having downwardly convergent sides, said slab having a glass receiving trough in its upper portion, means for continuously introducing molten glass into the trough where it overflows the sides and flows down the sidesof the slab in stream-like formation,

means fixed to the slab and projecting outwardly beyond the sides of. the body-thereof for retarding the flow of glass down the sides of the slab for controlling temperature and thickness properties of the streams, and

means. for drawing the streams fromthe end of the slab in united sheet form.

17. In the art of drawing'sheet glass, a slab, means to flow a stream of glass down both sides of the slab, means on the slab and projecting outwardly beyond the sides of the body thereof for retarding the movement of the glass down the slab to control and equalize the thickness and temperature properties of the glass, and means for creating an edge portion, means for introducing molten glass' into the trough where it overflows and flows down the sides of the slab in stream-like for mation, and means for drawing the streams from the lower end of the slab in united sheet form, the side walls of said trough being curved and the bottom of said trough being arched to produce a more shallow depth of glass in the trough at the center than at its ends.

20. In apparatus for producing sheet glass,-

ice

fa .substantia1ly. vertically positioned slab having a glass receiving trough its upper fiporti'on, means for introducing molten glass "intothetroughwhere it overflows and flows 1' r 5 down the sides of the slab 'inst'rearn-like 01:- jt

' mation, means for drawing the streams from the lower end of the slab in unitedsheet form, V I'ne'ansTfiXedtothes1ab'and.projectingout- 1 wardly beyond the sides of the body-thereof 3 I: 0r,-' retarding ltheflowof fglass-down cthe I sides ofthe s1ab, the side walls of said trough I i' being curved :and the bottom of said trough being arched'toproducea more shallow depth of glass in the trough-at the center thanat its ends.' 1 1r. 21. apparatus for producing sheet glass, a. vsubstantially vertically positioned slab having downwardly convergent sides," means a v for flowing molten glass in stream like forv 2 mation down the sides of-the slab, means for '.-drawing the streams from, the lower end of 1 r -the's1ab inunited sheet form, shoes positioned f' opposite the edge portionsot the'strearns' V flowing down said slabfand means for inter- $2 nally cooling said shoes to efie'ctacooling of the edge portions of the glass streams. p I i A 22. In apparatusfor producing sheet glass, 7

substantially vertically positioned slab v having downwardly convergent. sides, means ".3 [for flowing molten glass in stream-like -for- I mation down the sidesof the slab, means for 7 :drawing the streams from' the lower end 'of, the-slab in united sheet form, shoesipositioned i opposite the edge portions of the streams; c ,35 flowing down said slab, means for internally Q I i cooling. said shoes to effect -a cooling of'the edge'portions of the glass streams,-and means 'lforfadjustingsaid shoes toward and away *from the; slab and for maintaining them in desiredadjusted position. a

r 23. In apparatus for forming sheet glass, afslab provided with a chamber attits top I and with downwardly convergingsides, an enlarged portion formed on the converging sidesand extending transversely thereof, and

means for establishin'ga fiow'of glass to the a r V chamber formedin the slab and thence down- I s 'wardly along'thesides of. the slab and upon the enlarged portion and 'thence to thebotv tom edge of the slabwhererthe. flowing glass 7 j unites intosinglesheet form; r Signed at Toledo,in the county of Lucas, v [and State of-Ohio, this 27th day of October,

5-1924. r is 1 r ENOCH rniinnennn, 

